PowerCore Essential 20000 PD strange behavior

Hi guys! I hope this is the right section to post this thread and I hope I can get some help :frowning: I’ve bought from Amazon a PowerCore Essential 20000 PD two weeks ago and I’ve been happily using it since today when I noticed something strange. The powerbank was charged up to 3 LED indicators ON (3 of the 4 total) so, in a worst case scenario, it should have had at least half of the capacity, 10000 mAh. I’ve put my Oneplus 6T on charge with 20% battery left but when my phone reached 86%, the powerbank was totally drained. I noticed this when I unlocked my phone to reply to some messages and noticed that it also stopped charging. So I gave a look at the powerbank and all leds were off…pressing the button just made the first led blink few seconds. The OnePlus 6T has a battery of 3700mAh so half powerbank capacity should have provided somewhere near 2,5 complete charges.
I’m disappointed honestly, since this Anker powerbank costed me some money and I thought spending more on a brand like Anker could get me some quality :pensive:

Someone had this problem before? I don’t know if I should contact Anker support immediately or try to stress the powerbank again and see if the problem occurs again. Just for info, I charge the powerbank with my Nexus 6P original charger which is a 5V 3A charger.

Use the 2/3rds rule.

So the OP6T should get 3 and half recharges. 20000 / 3700 X 2 / 3 = 3.6

Using the same assumption of 20000 half charged you’d expect just under 2 phone recharges.

Reasons to get less could be (most probable) the cable, so try different cable. Or you were using the phone while being charged so you got actually more energy than just battery recharge. Or product has issues.

Suggest try different cable, and fully recharge the 20000 before testing and count recharges while NOT using phone.

If after trying that, and still issues then email support@anker.com and quote your order details, serial number off package, and sure they’ll sort you out.

Thank you for the fast reply. So, from a 20000 mAh powerbank, I can expect somewhere near 13300, little over half of the listed capacity…very very disappointing :frowning:
Anyway I forgot to mention that I almost didn’t touch the phone during it’s charge to 86%, just few times to reply to some text messages (so nothing stressful anyway).

I’ll do some more testing without touching the phone at all, with a different cable, as you suggested. I’ve used the usb-c cable provided with the powerbank but I’ll use the original OP6T charger red cable. Currently I’m charging the powerbank with a regular 5V 2,4 A wall charger and I’m still waiting for it to fully charge.

Watch the video.

No this 20000 PD needs charging with a 18W PD charger, otherwise your next comment will be the 20000 PD is taking a long time to recharge.


Thank you for the infos!

There’s something odd with my 20000 Essential PD.

So I am cycling through all my Powercore, I have the 26800, 10000 PD, 10000 PD Slim and the 20000 Essential PD. I know to store them at room temperature and not leave them idle for too long “keep the electrons moving” so I rotate between these as my Powercore to use on the day.

It came the turn of my 20000 Essential PD turn to get drained and I used it for 1 whole day on my large tablet and it got flat. I didn’t think much of it until I then get next to my 26800. It is now on it’s 2nd day and 3 of 4 lights on. Different cables (C-C vs A-C). This is counter-intuitive as the 26800 is now over 3 years old so I’d be expecting to be showing signs of capacity loss by now and begin to lose to a newer 20000.

This could be the voltage conversion losses. The 20000 PD I was using its 18W 9V 2A port, the tablet has a 3.85V cell so I am wondering if 5V would be more efficient than 9V?

I own USB meter I use to debug cables and my cables all good. But my USB meter do not measure mAh, only I look at V and A. So I cannot measure capacity.

My large tablet lasts roughly a day on its battery 7300mAh, so I’d expect (2/3rds rule) 10000mAh to last a day and 20000 to last 2 days. So the 26800 being about half full after a full day feels right, but a 20000 flat in a day feels wrong. It could be the 5V being more efficient?

Anker sent me the 20000 generously as a surprise pleasant Xmas gift so I don’t want to raise a support ticket (feels wrong to).

Anyone have a similar concern?

This might be my time to buy another better USB meter which counts Wh to work out the most efficient combination of port and cable. e.g. the 20000 Essential may be more efficient on its Type A port, and that is not necessarily the fault Anker, it could be an efficiency issue within the device, which a USB meter can never measure.

I’m not an expert at battery’s and charging and such, but I haven’t had any issues with my 20000 PD battery.

Also just a comment from a previous conversation. Charging my 20000 PD and 10000 PD powerbanks with PIQ3, takes the same amount of time advertised on amazon (so no issues with PIQ3 here).


There’s only so much of a conclusion I can form, it could be the device stepping down from 9V to 3.85V is less efficient than stepping down from 5V, I cannot measure that. I can though count Wh from the 20000 to the device if I got a better USB meter.